Drilling ice cores is a tedious task. It takes years of fieldwork to recover long ice tubes that hold a continuous climate record spanning hundreds of thousands of years.
Super-fast polar drills
These speedy tools take about a week instead of years to penetrate several kilometers of ice. They break through the upper layers of ice to reach the ancient ice below, where trapped air bubbles act as time capsules for long-gone environments.
Drills sacrifice detail for speed
These fast drills break or melt the ice while drilling, making it impossible to extract an intact core. But these speedy drills will be able to conduct quick surveys of locations that researchers may return to in future field seasons to extract complete ice cores at a more leisurely pace. For example, the $10.5 million American RAID drill is designed to penetrate over 3 kilometers of ice in about a week. This speed will allow it to hop around Antarctica and drill several exploratory holes each season instead of one hole over multiple seasons.
Current and future polar drills
American and British drills are taking different approaches to reach Antarctica’s deep past. Once the American RAID drill reaches the bottom of the ice, it can drill up to 50 meters into the bedrock. Analyzing those rocks can reveal when they were last exposed to cosmic rays—which in turn reveals the age of the overlying Antarctic ice. The full-size RAID is set to be tested for the first time in the 2016-2017 season.
In contrast, the British RAID project is a more modest project costing less than £500,000 ($770,000) and uses a modified traditional ice core drill. It will only be able to penetrate about 600 meters into ice that is 30,000 to 40,000 years old—but unlike the American RAID, it does not require drilling fluid, which adds weight to the drill and increases transport costs. “You can’t drill dry deeper than that,” says Julius Rex, the engineer leading the drill’s development.
There is a third project, known as SUBGLACIOR, which is a similarly sized project to the American drill, being developed at Joseph Fourier University in Grenoble, France. This €3.2 million ($5.3 million) project aims to melt the ice rather than break it while drilling, measuring the chemical isotopes of the melted water during drilling to calculate the age of the ice. The drill will be able to penetrate several kilometers deep; full tests are scheduled for the 2016-2017 season at the Concordia research station in Antarctica, according to Olivier Aleman, a polar engineer at Joseph Fourier University.
A fourth project, known as RADIX, will use a much narrower hole than other drills—only 2 centimeters in diameter—to drill up to 3 kilometers within a few days. Limited tests of RADIX have been conducted in Greenland, according to team leader Jakob Schvander, a climatologist at the University of Bern.
No one knows exactly what these drills will encounter when they reach the bottom. They might penetrate pure lakes beneath the ice, which microbiologists could explore. Or they could reveal heat radiating from the bedrock, melting the ice in ways scientists do not expect.
“It’s incredibly interdisciplinary,” according to John Goodge, a geologist at the University of Minnesota Duluth and the leader of the American RAID project. “There are all kinds of things that this fast technology enables that we haven’t been able to get before.”
Source:
https://www.nature.com/news/super-fast-antarctic-drills-ready-to-hunt-for-oldest-ice-1.18649
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